Method of manufacturing polychrome screens for color photography and cinematography



Sept. 1,1925. 1,552,126

L. DUFAY METHOD OF MANUFACTURING POLYCHROME SCREENS FOR COLOR PHOTOGRAPHY AND CINEMATOGRAPHY Filed April 22. 1924 lllllllllllllllllllllllllllllllllllllllllllll|||||||||||I|||l|||| I ZZue T607 or rye 3 760 1* W'aZef 5/06 w'olef rfoZet $.27ufay I g 7% Patented Sept. 1, 1925.

' UNITED STATES rA'r'su'r orlcs'.

LOUIS purer, ,o-r vnnsa nnnsjrna'ncn METHOD OF MANUFACTURING TOLYGHROME SCREENS FOR COLOR PHOTOGRAPHY AND CINEMA'IOGRAPHY.

Application filed April 22, 1924. Serial No. 768,254.

ink, gelatin, celluloid, gum, etc., regularly arranged or distributed on a transparent support or. carrier, of glass or celluloid. These colored elements forming a mosaic work, constitute therefore, a special layer which is caused to adhere to the transparent support by suitable means, such as glue, impression, etc:

It has also been proposed to obtain polychrome screensby placing greasy reserves on the transparent. support and then coloring the uncovered part of said support.

The whole is then coated with a varnish,

the character of which is such asto permit the removal or elimination of the reserves originally applied, and then the parts of the support already colored are protected by this varnish.

The elimination of the first reserves then permits the coloring of the parts of the film which the varnish does not cover. necessary in. obtaining. very small colored elements, to bring the. close to each other, thelr elimination or removal, without damaging the varnish, would be very difiicult, and wouldalways produce partial breaks or complete elimination of these greasy elements.

It has also been proposed to apply greasy reserves on a transparent support with a complementary color, saidreserves permit ting the de-coloration of the nonrotected parts and their coloring with anot er complementary color. This method results only in'a three colored screen and the elements of the same color do not cover the same total surface as the elements of another color. The screen would not, hence, be homogeneous from a chromatic point of view.

The present invention has for its ob'ect, a four-color polychromescreen which is characterized in that there are applied on Asit is" easy reserves very.

a transparent support, coated with a primary color, greasy reserves, so as to permit de-colorizingthe parts not covered by the reserves,- and then coloring'said parts with another primary color. After eliminating the greasy reserves, the two primary color screen thus obtained, is colored over its entire surface, with a third primary color, thus resulting in a screen of two complementary colors. On this screen I apply greasy'reserves and eliminate the third pri-- mary color, on the parts which are not covered by the greasy reserves.- In these parts, I then cause the two first primary colors to re-appear, and I color these latter with a complementary color of the third primary color used. After eliminating the reserves, I obtain a screen of four complementary colors.

Thefirst group of colors may be constituted by red and yellow and the second group by blue and its complementary color, orange. Or if desired,- the first group may be yellow and blue and the second group be red and its complementary color green. Furthermore,.the colored elements may be of any shape, geometrical or not, regular or irregular. 1

In case' it is desired to obtain the particular chromatic system; blue and red, yellow and violet, the process consists of the series of steps illustrated diagrammatically in Figs. 1 to 7 of the accompanying drawings.

One face of a transparent support, such as .a sheetof film or glass as willbe uniformly is'removed from these sections I coat these parts with another primary color (1, red for example. The reserves 1) are then eliminated or removed and I thus obtaina screen in two rimary colors, red and blue stripes in this instance, (see Fig. 3

The removal of t eblue between the reserves, that is, from the parts not pccu ied by the reserves, may be accornphshe using potassium hydrate or sodium hydrate.

color .for the blue will be eflected nearlyinstantaneously by adding to the red, a small proportion of an alkali-sodium hydrate or lines at any suitable angle (Fig. 5).

potassium hydrate. v

This surface which now consists of alternate red and blue stripes is then coated with an alcoholic solution of yellow dye stuff or color which will convert the blue into green e and the red into orange f (Fig. 4

Then on the screen thus prepared, I typographically print a new series of greasy lines a which cross the green and orange Then the surface thus treated is subjected to the action of a blue-violet coloring bath of such chemical nature that it destroys the yellow and takes its place in the portions not protected by the easy ink, which alone, will be pervious ig. 6). In the non-protected portions, the sub-adjacent red and blue divisions will persist after elimination of the yellow and will reinforce the selecting power of the blue-violet, without modifyin their own selection or absorption ban s.

There will then only remain the elimination of the series of greasy lines, and the network, thus produced will be incorporated and impermeabilized in the mass of the transparent support or base, without any black or colorless space, and will present selecting elements colored green, orange, violet-blue andviolet-red (Fig. 7)..

This network or screen can be used for all photographic and cinematographic uses and mag be emulsified in the ordinary manner. f course, the combination of dye stufis or colors can be varied, and instead of a series of greasy lines for reserves, I may use said .00 ored surface, eliminatin as reserves, figures, either'geometrical or not, and regular or irregular.

What I claim as m invention and desire to secure by ,Lettersatent is:

1 In a method of manufacturing polychrome screens for cinematography, coating one face of a trans arent support with a primar color, placing greasy reserves on said primary color from the parts of t e support not covered by the reserves, then colorin with another primary color the parts 0 Lemma the support not covered by the'reserves, and

alkali.

e 3. In a method as claimed in claim 1,.the

added step of coating the entire surface of thetwo color screen with a third primary color to obtain a screen of two complementary colors. 1

4'. In a method as claimed in claim 1, the added step of coloring the .entire surface of the two color screen with a third primary color to obtain a screen of two complementary colors, and then'applying greasy reserves on the screen of two. complementary colors. w

5. A method of manufacturing polychrome screens for color photography consisting in coating a transparent sheet with a primary color, placing greasy reserves on said coating, using an alkali to eliminate said primary color on the parts of the sheet not covered by the reserves, then coloring with another primary color, the parts of the sheet from which said primary color has been eliminated, then removing the reserves to obtain a screen of two pr mary colors, then coating the entiresurface of the "two color screen with a third primary color to obtain a screen of two complementary colors, applying a second series of fatty reserves on the screen of two complementary colors, and then eliminating the third primary color in the parts not covered by the second series of reserves to cause the first two primary colors to reappear.

6. A method as claimed in claim 5 in which the third primary color in the parts not covered by the second series of reserves is eliminated by the use of an alkali.

7. A method as claimed in claim 5 1n which the parts not covered by' the second reserves are colored with a fourth color complementa to the third color used, and finally eliminating the second series of greas reserves to obtain a screen of four comp ementary colors.

In testimony whereof I have signed my name to thisspecification.

LOUIS DUFAY. 

